CPU frequency control ?

[Vincent Trouilliez]

I still don't have a clear understanding of cpu freq control, I hope
someone can clarify it for me :

1) Is it a feture tha only applies to laptops, or also to desktops (what
I am interested in in this cas) ?

2) what does it depend on : ACPI BIOS and/or chpiset and/or cpu brand
type model ?

If desktop CPU's support this feature, then, considering that my current
CPU, an AMD Athlon XP 1700+ clearly doesn't support it, when did
Intel/AMD start building this feature into their CPU.
Objective being, to change my motherboard, and put the oldest, read
cheapest, CPU, that can support power/frequency management.

Intel CPU's are too expensive so will stick with AMD. 
The AMD "64" are way too expensive, AMD "Opteron" too. However the
Athlon XP "Sempron" and "Barton" are affordable (kinda). Does any of
these two CPU's support frequency/power control ?

Also, for a given frequency, which CPU dissipates the more power/heat, a
Pentium 4 or an Athlon XP ?

Thanks for any info...

Vince




Le lundi 06 décembre 2004 à 01:56 -0800, Karl Hegbloom a écrit :
> FWIW, I've got a laptop that used to work with the Centrino cpufreq
> module, but did a BIOS upgrade, and that suddenly quit working.  I'm
> pretty sure it's because somehow the BIOS upgrade changed the CPU ID
> string...  (It's funny; when it boots now it says "enuine Intel ..."; I
> guess with all this Free Software, it has run low on G's?)
> 
> Anyway, back to the point... what I found is that the ACPI cpufreq
> module works very well.  In fact, I would guess (I have only one laptop
> to try it on) that it would make a good default.
> 
> I'm using the cpufreq-applet.  It does not monitor temperature, but does
> show the frequency and lets me set it.  I'm using cpudynd for speed
> control.  I have not tried powernowd.
> 
> (I have not changed this laptop to Ubuntu yet --- I must wait until
> after finals to make that step.)
> 
> -- 
>      Karl Hegbloom                 ,''`.
> (o_   mailto:hegbloom at pdx.edu      : :' :
> //\    jabber:karlheg at jabber.org   `. `'
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> 
>